pseudocyphella

from The Century Dictionary.

• noun A small depression in the under surface of a lichen thallus, differing from a cyphella in being pulverulent or bearing soredia.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A structure in lichens that appears as a tiny pore on the outer surface, caused when there is a break in the cortex of the lichen and the medullary hyphae extend to the surface.